After releasing their third studio album earlier this year, Plastic Beach, Gorillaz this week finally kicked off their much-anticipated world tour last weekend in Montreal (they’re also due to perform a Live on Letterman webcast Oct. 7). But that wasn’t all–today they slipped a new song into the world, the curiously titled “Doncamatic (All Played Out).”Give a listen–and find out just what a Doncamatic really is.“Doncamatic” premiered today on Zane Lowe’s Hottest Record in the World show on the BBC’s Radio 1. The title comes from a curious (and at the time cutting-edge) rhythm machine, the Doncamatic, unleashed by the Korg Musical Instrument Company in 1963.According to the band’s YouTube channel, the song features a “hot new British talent” named Daley; it was recorded just “a few weeks ago” and the band “wanted to unleash it onto the world as soon as humanly possible.”Watch the Gorillaz perform songs from throughout their catalog during their Live on Letterman concert webcast,  which kicks off on CBS.com October 7 at 8pm ET (5pm PT).The Gorillaz Live on Letterman is presented by AT&T.